How to solve JavaScript error: Unable to get value of the property '': object is null or undefined?

There are normally two reasons to cause this problem:
1. Lost reference of needed JavaScript library.
2. The reference JavaScript library is not loaded when your script run.

How to set and get selected value in dropdown list by jQuery

Set selected value:
var selectstring = 'select option[value="' + selectedValue + '"]';
$(selectstring).attr('selected', true);

Get selected value:
$("#dropdownlistId").change(function () {
alert($("#dropdownlistId").val());
});

Javascript Cookie helper

function createCookie(name,value,days) {
 if (days) {
  var date = new Date();
  date.setTime(date.getTime()+(days*24*60*60*1000));
  var expires = "; expires="+date.toGMTString();
 }
 else var expires = "";
 document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
 var nameEQ = name + "=";
 var ca = document.cookie.split(';');
 for(var i=0;i < ca.length;i++) {
  var c = ca[i];
  while (c.charAt(0)==' ') c = c.substring(1,c.length);
  if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
 }
 return null;
}

function eraseCookie(name) {
 createCookie(name,"",-1);
}

Reference:
http://www.quirksmode.org/js/cookies.html

What is PO file?

PO file is the file format to save message for internationalization and localization (I18n, L10n)

It is from a open source project: gettext
http://www.gnu.org/software/gettext/

The format like:
# translator-comments
#. extracted-comments
#: reference...
#, flag...
#| msgid previous-untranslated-string
msgid untranslated-string
msgstr translated-string

Example:
#: lib/error.c:116
msgid "Unknown system error"
msgstr "Error desconegut del sistema"


It is very friendly for developer and translator working together, and also make code more readable. To ASP.NET developer is another choice than resource file.

The Evolution of a Programmer

http://www.ariel.com.au/jokes/The_Evolution_of_a_Programmer.html